Isotope domain mapping of ⁸⁷ Sr/ ⁸⁶ Sr biosphere variation on the Isle of Skye, Scotland

Abstract

The potential of 87 Sr/ 86 Sr isotope composition for tracking and determining the origin of material, whether it is humans, animals, water or wine can be fully realized only if high-quality reference datasets are available against which to compare the unknowns. This is currently not the case. Despite the rapid increase in 87 Sr/ 86 Sr-based provenance studies of biosphere materials there are no well-documented maps available. Most researchers resort to generating reference maps from a variety of geological datasets plus the analysis of sparse 'environmental' samples. A major reason for this lack of reference material is the investment needed to undertake systematic sampling and analysis over large areas. A further problem is associated with the choice of proxy material, as organisms differ in their habitat and exploitation of resources. In this paper various approaches to isotope biosphere sampling are considered, some of the problems are assessed, the precision required for the study of human populations is discussed, and a first attempt is made to condense all of the available information into an 'isotope package' map. The work is based on a study undertaken on the Isle of Skye, in the Inner Hebrides, and reduces the complexity of geological and isotope data into five main 87 Sr/ 86 Sr packages: Package 1 (northern area) ¼ 0.705-0.7092; Package 2 (NE coast) ¼ 0.7082-0.7102; Package 3 (granitic rocks) ¼ 0.716-0.720; Package 4 (metamorphic rocks) ¼ 0.7092-0.7188; Package 5 (seawater) ¼ 0.7092 AE 0.005% (2ó). The approach of trying to constrain the isotope composition of certain areas and/or lithologies offers the possibility of extrapolating to other similar areas without having to sample at the original density.

Cattle mobility in prehistoric Britain: strontium isotope analysis of cattle teeth from Durrington Walls (Wiltshire, Britain)

“…Blank values were in the region of 100 pg. Vegetation samples used to establish the local strontium signature around Durrington Walls were analysed following the method described in Evans et al (2009).…”

Mapping multiple source effects on the strontium isotopic signatures of ecosystems from the circum‐Caribbean region

“…87 Sr/ 86 Sr) have been increasingly and successfully employed as provenance tracers of a wide variety of environmental processes (Graustein and Armstrong 1983, Kelly et al 2005, Bentley 2006 (Price et al 2002, Hodell et al 2004, Bentley 2006, Evans et al 2009). …”

87Sr/86Sr and trace element mapping of geosphere-hydrosphere-biosphere interactions: A case study in Ireland

“…Åberg et al 1998;Bentley & Knipper 2005;Evans et al 2009;Evans et al 2010;Frei & Frei 2011;Frei & Frei 2013;Hartman & Richards 2014;Hedman et al 2009;Hodell et al 2004;Knudson & Torres-Rouff 2009;Kootker et al 2016;Laffoon et al 2012;Nafplioti 2011;Porder et al 2003;Price and Naumann, 2015;Sjögren et al 2009;Thornton 2011;Voerkelius et al 2010;Willmes et al 2014;Zitek et al 2015), however none of these has specifically dealt with detailed Sr isoscapes in Ireland. At present, there are relatively few published data dealing with spatial variation of 87 Sr/ 86 Sr in the Irish biosphere using environmental samples (Cahill Wilson and Standish, 2016;Knudson et al, 2012;Snoeck et al, 2016;Voerkelius et al, 2010), despite the fact that 87 Sr/ 86 Sr are commonplace as a provenance tool applied to archaeological studies (e.g.…”